-alevels a a = number of levels of factor A
-blevels b b = number of levels of factor B
-clevels c c = number of levels of factor C
-dset 1 1 1 filename data set for level 1 of factor A
and level 1 of factor B
and level 1 of factor C
. . . . . .

-dset i j k filename data set for level i of factor A
and level j of factor B
and level k of factor C
. . . . . .

-dset a b c filename data set for level a of factor A
and level b of factor B
and level c of factor C

[-OK] confirm you understand that contrasts that
do not sum to zero have inflated t-stats, and
contrasts that do sum to zero assume sphericity
(to be used with -old_method)

[-assume_sph] assume sphericity (zero-sum contrasts, only)

This allows use of the old_method for
computing contrasts which sum to zero (this
includes diffs, for instance). Any contrast
that does not sum to zero is invalid, and
cannot be used with this option (such as
ameans).

N.B.: For this program, the user must specify 1 and only 1 sub-brick
with each -dset command. That is, if an input dataset contains
more than 1 sub-brick, a sub-brick selector must be used, e.g.:
-dset 2 4 5 'fred+orig[3]'

INPUT DATASET NAMES
-------------------
This program accepts datasets that are modified on input according to the
following schemes:
'r1+orig[3..5]' {sub-brick selector}
'r1+orig<100..200>' {sub-range selector}
'r1+orig[3..5]<100..200>' {both selectors}
'3dcalc( -a r1+orig -b r2+orig -expr 0.5*(a+b) )' {calculation}
For the gruesome details, see the output of 'afni -help'.
-------------------------------------------------------------------------
STORAGE FORMAT:
---------------
The default output format is to store the results as scaled short
(16-bit) integers. This truncantion might cause significant errors.
If you receive warnings that look like this:
*+ WARNING: TvsF[0] scale to shorts misfit = 8.09% -- *** Beware
then you can force the results to be saved in float format by
defining the environment variable AFNI_FLOATIZE to be YES
before running the program. For convenience, you can do this
on the command line, as in3dANOVA -DAFNI_FLOATIZE=YES ... other options ...
Also see the following links:https://afni.nimh.nih.gov/pub/dist/doc/program_help/common_options.htmlhttps://afni.nimh.nih.gov/pub/dist/doc/program_help/README.environment.html